The structure & development of the mosses and ferns (Archegoniatae) . Fig. 221.—Development of the autheridium, X 190. A, Longitudinal section through the antheridia!meristem showing antheridia of different ages ; B, longitudinal section of young antheridium,X375 ; C, two sections of a terminal, single antheridium, nearly ripe, X190 ; D, threetransverse sections of young antheridium, X 190 ; 0, opercular cell. eusporangiate Ferns, the antheridium mother cell is dividedinto an inner and an outer cell, of which the inner one forms atonce the sperm cells. When the antheridium arises at the endof
The structure & development of the mosses and ferns (Archegoniatae) . Fig. 221.—Development of the autheridium, X 190. A, Longitudinal section through the antheridia!meristem showing antheridia of different ages ; B, longitudinal section of young antheridium,X375 ; C, two sections of a terminal, single antheridium, nearly ripe, X190 ; D, threetransverse sections of young antheridium, X 190 ; 0, opercular cell. eusporangiate Ferns, the antheridium mother cell is dividedinto an inner and an outer cell, of which the inner one forms atonce the sperm cells. When the antheridium arises at the endof a filament, the divisions in the terminal cell are very muchlike those in Osmunda. In the mother cell three intersectingwalls enclose a tetrahedral cell, which then has the cover cellcut off by a periclinal wall. In both forms of antheridium thesubsequent history is the same. The central cell divides firstby a transverse wall, followed by vertical walls in each cell, andsubsequently by numerous divisions which show no definitearrangement (Fig. 221, C), and produc
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Keywords: ., bookcentury1800, bookdecade1890, bookidstructuredev, bookyear1895
